I. Field of the Invention
The present invention relates to cellular communication systems, and, more particularly, to a novel and improved method and apparatus for providing redundant coverage within a cellular communications system using a sectored antenna arrangement array.
II. Description of the Related Art
In cellular communication systems, communication between a base station and subscriber units is facilitated by partitioning the surrounding cell into "sectors". Referring to FIG. 1, there is shown a first exemplary cell 10 in which are disposed a plurality of subscriber units 12 and a base station 14. As is indicated by FIG. 1, the cell 10 is partitioned into six sectors S1-S6. The base station 14 may include a set of six fixed-beam antennas (not shown) dedicated to facilitating communication with subscriber units in the sectors S1-S6, respectively.
Within the base station 14, a separate communications transceiver will typically be coupled to each of the fixed-beam antennas. Each communications transceiver is responsible for processing the information signals exchanged between the base station 14 and the subscriber units 12 within a particular sector. Each communications transceiver will generally include, for example, signal amplifiers, frequency up/downconverters, and baseband signal processing apparatus.
Since each communications transceiver is dedicated to a particular sector, the failure of one of the transceivers results in the interruption of service to the subscriber units 12 within the associated sector. Accordingly, in order to prevent service interruption it has been common practice to provide redundant communications hardware within each cell-site base station. For example, in the event of failure of a high-power amplifier (HPA) within a given communications transceiver, a spare HPA may be switched into the transceiver during replacement of the inoperative HPA.
Unfortunately, the provision of spare communications hardware within each cell-site increases system cost and complexity. Moreover, since identification of the specific hardware element causing a given communications transceiver to become inoperative may require sophisticated monitoring apparatus, it is often necessary to provide at least one entire redundant transceiver unit.
It is therefore an object of the present invention to provide a method and apparatus for providing redundant sector coverage within a cellular communications system without reliance upon spare communications hardware.